ATP-sensitive K+ channel (KATP channel) is an inwardly rectifying K+ channel connecting intracellular metabolism and cell-membrane excitation and known to have a heterologous octamer structure constituted of a sulfonyl urea receptor (SUR) belonging to an ABC protein family and two-span transmembrane subunits Kir6.1 and Kir6.2. The activity of the KATP channel is controlled by various types of K+ channel openers, inhibitors or intracellular nucleotides. All of these have active sites in SUR subunits. It has been reported that the reactions of them differ depending on the subtype of SUR (NPL 1).
Some of adamantane derivatives having a cage type structure are used as medical drugs. Amantadine is used as antiviral drug and a therapeutic agent for Parkinson's disease. Memantine hydrochloride has been approved as a therapeutic agent for moderate/severe Alzheimer's dementia even in Japan. Memantine is a noncompetitive NMDA-receptor inhibitor and reported to have an action mechanism which prevents neuronal cell death of excessive glutamic acid release caused by ischemia (NPL 2).
Adamantane derivatives having an activity as a medical drug are reported in several literatures (PTLs 1 to 3).